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*/

/** @file ParsingUtils.h
 *  @brief Defines helper functions for text parsing
 */
#pragma once
#ifndef AI_PARSING_UTILS_H_INC
#define AI_PARSING_UTILS_H_INC

#ifdef __GNUC__
#pragma GCC system_header
#endif

#include <assimp/StringComparison.h>
#include <assimp/StringUtils.h>
#include <assimp/defs.h>

#include <vector>
#include <algorithm>

namespace Assimp {

/// NOTE: the functions below are mostly intended as replacement for
/// std::upper, std::lower, std::isupper, std::islower, std::isspace.
/// we don't bother of locales. We don't want them. We want reliable
/// (i.e. identical) results across all locales, because we had a lot 
/// of issues in the past .

/// The functions below accept any character type, but know only
/// about ASCII. However, UTF-32 is the only safe ASCII superset to
/// use since it doesn't have multi-byte sequences.

static constexpr unsigned int BufferSize = 4096;

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is upper-case.
/// @param  in  The character to test.
/// @return true if upper-case, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsUpper(char_t in) {
    return (in >= (char_t)'A' && in <= (char_t)'Z');
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is lower-case.
/// @param  in  The character to test.
/// @return true if lower-case, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsLower(char_t in) {
    return (in >= (char_t)'a' && in <= (char_t)'z');
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a space.
/// @param  in  The character to test.
/// @return true if a space, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsSpace(char_t in) {
    return (in == (char_t)' ' || in == (char_t)'\t');
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a line end.
/// @param  in  The character to test.
/// @return true if a line end, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsLineEnd(char_t in) {
    return (in == (char_t)'\r' || in == (char_t)'\n' || in == (char_t)'\0' || in == (char_t)'\f');
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a space or a line end.
/// @param  in  The character to test.
/// @return true if a space or a line end, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsSpaceOrNewLine(char_t in) {
    return IsSpace<char_t>(in) || IsLineEnd<char_t>(in);
}

// ---------------------------------------------------------------------------------
/// @brief Will skip all spaces in a buffer.
/// @param in     The incoming buffer.
/// @param out    The  buffer with skipped data.
/// @param end    The end of the buffer.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipSpaces(const char_t *in, const char_t **out, const char_t *end) {
    while (in < end && (*in == (char_t)' ' || *in == (char_t)'\t')) {
        ++in;
    }
    *out = in;
    return ((in < end) && !IsLineEnd<char_t>(*in));
}

// ---------------------------------------------------------------------------------
/// @brief Will skip all spaces in a buffer in-situ.
/// @param inout     The in/out buffer.
/// @param end    The end of the buffer.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipSpaces(const char_t **inout, const char_t *end) {
    return SkipSpaces<char_t>(*inout, inout, end);
}

// ---------------------------------------------------------------------------------
/// @brief Will skip a line.
/// @param in     The incoming buffer.
/// @param out    The  buffer with skipped data.
/// @param end    The end of the buffer.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipLine(const char_t *in, const char_t **out, const char_t *end) {
    while ((*in != (char_t)'\r' && *in != (char_t)'\n' && *in != (char_t)'\0') && *in != (char_t)'#' && in != end) {
        ++in;
    }

    // files are opened in binary mode. Ergo there are both NL and CR
    while (in < end && (*in == (char_t)'\r' || *in == (char_t)'\n')) {
        ++in;
    }
    *out = in;
    return in < end && *in != (char_t)'\0';
}

// ---------------------------------------------------------------------------------
/// @brief Will skip a line in-situ.
/// @param in     The in/out buffer.
/// @param end    The end of the buffer.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipLine(const char_t **inout, const char_t *end) {
    return SkipLine<char_t>(*inout, inout, end);
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a space or a line end.
/// @param  in  The character to test.
/// @param  out The buffer with the skipped data.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipSpacesAndLineEnd(const char_t *in, const char_t **out, const char_t  *end) {
    while (in < end && (*in == (char_t)' ' || *in == (char_t)'\t' || *in == (char_t)'\r' || *in == (char_t)'\n')) {
        ++in;
    }
    *out = in;
    return in < end && *in != '\0';
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a space or a line end.
/// @param  in  The character to test.
/// @param  out The buffer with the skipped data.
/// @return true if valid.
template <class char_t>
AI_FORCE_INLINE bool SkipSpacesAndLineEnd(const char_t **inout, const char_t *end) {
    return SkipSpacesAndLineEnd<char_t>(*inout, inout, end);
}

// ---------------------------------------------------------------------------------
/// @brief Will return point showing to the next line.
/// @param buffer    The in buffer.
/// @param out       The next line.
/// @return true if a new lne was found, else false.
template <class char_t>
AI_FORCE_INLINE bool GetNextLine(const char_t *&buffer, char_t out[BufferSize]) {
    if ((char_t)'\0' == *buffer) {
        return false;
    }

    char *_out = out;
    char *const end = _out + BufferSize - 1;
    while (!IsLineEnd(*buffer) && _out < end) {
        *_out++ = *buffer++;
    }
    *_out = (char_t)'\0';

    while (IsLineEnd(*buffer) && '\0' != *buffer && buffer != end) {
        ++buffer;
    }

    return true;
}

// ---------------------------------------------------------------------------------
/// @brief  Returns true, if the character is a number.
/// @param  in  The character to test.
/// @return true if a number, false if not.
template <class char_t>
AI_FORCE_INLINE bool IsNumeric(char_t in) {
    return (in >= '0' && in <= '9') || '-' == in || '+' == in;
}

// ---------------------------------------------------------------------------------
/// @brief Will check an incoming buffer for a given token.
/// @param in        The incoming buffer.
/// @param token     The token to check for.
/// @param len       the buffer length.
/// @return true if token was found, false if not.
template <class char_t>
AI_FORCE_INLINE bool TokenMatch(char_t *&in, const char *token, unsigned int len) {
    if (!::strncmp(token, in, len) && IsSpaceOrNewLine(in[len])) {
        if (in[len] != '\0') {
            in += len + 1;
        } else {
            // If EOF after the token make sure we don't go past end of buffer
            in += len;
        }
        return true;
    }

    return false;
}
// ---------------------------------------------------------------------------------
/// @brief Case-ignoring version of TokenMatch
/// @param in    Input
/// @param token Token to check for
/// @param len   Number of characters to check
/// @return true if token was found, false if not.
AI_FORCE_INLINE bool TokenMatchI(const char *&in, const char *token, unsigned int len) {
    if (!ASSIMP_strincmp(token, in, len) && IsSpaceOrNewLine(in[len])) {
        in += len + 1;
        return true;
    }
    return false;
}

// ---------------------------------------------------------------------------------
/// @brief Will skip the next token.
/// @param in   The incoming buffer.
/// @param end  The end marker of the buffer.
AI_FORCE_INLINE void SkipToken(const char *&in, const char *end) {
    SkipSpaces(&in, end);
    while (!IsSpaceOrNewLine(*in)) {
        ++in;
    }
}

// ---------------------------------------------------------------------------------
/// @brief Will return the next token as a string.
/// @param in    The incoming buffer.
/// @param end  The end marker of the buffer.
/// @return The next token.
AI_FORCE_INLINE std::string GetNextToken(const char *&in, const char *end) {
    SkipSpacesAndLineEnd(&in, end);
    const char *cur = in;
    while (!IsSpaceOrNewLine(*in)) {
        ++in;
    }
    return std::string(cur, (size_t)(in - cur));
}

// ---------------------------------------------------------------------------------
/// @brief  Will perform a simple tokenize.
/// @param  str         String to tokenize.
/// @param  tokens      Array with tokens, will be empty if no token was found.
/// @param  delimiters  Delimiter for tokenize.
/// @return Number of found token.
template <class string_type>
AI_FORCE_INLINE unsigned int tokenize(const string_type &str, std::vector<string_type> &tokens,
        const string_type &delimiters) {
    // Skip delimiters at beginning.
    typename string_type::size_type lastPos = str.find_first_not_of(delimiters, 0);

    // Find first "non-delimiter".
    typename string_type::size_type pos = str.find_first_of(delimiters, lastPos);
    while (string_type::npos != pos || string_type::npos != lastPos) {
        // Found a token, add it to the vector.
        string_type tmp = str.substr(lastPos, pos - lastPos);
        if (!tmp.empty() && ' ' != tmp[0])
            tokens.push_back(tmp);

        // Skip delimiters.  Note the "not_of"
        lastPos = str.find_first_not_of(delimiters, pos);

        // Find next "non-delimiter"
        pos = str.find_first_of(delimiters, lastPos);
    }

    return static_cast<unsigned int>(tokens.size());
}

// ---------------------------------------------------------------------------------
/// @brief  Will convert the given string to lowercase with stl-strings.
/// @param  str    The stl-string to convert.
/// @return The lowercase string as a stl-string.
inline std::string ai_stdStrToLower(const std::string &str) {
    std::string out(str);
    for (size_t i = 0; i < str.size(); ++i) {
        out[i] = (char) tolower((unsigned char)out[i]);
    }
    return out;
}

} // namespace Assimp

#endif // ! AI_PARSING_UTILS_H_INC
